Change credential pattern for openstack inventory plugin

See upstream docs https://github.com/ansible/ansible/pull/54532
Previously it was thought that the entry in the inventory config
file was necessary, but the upstream docs change allows us to
use the same pattern that we used to for the script.

awx/main/models/inventory.py

@@ -2508,26 +2508,25 @@ class openstack(PluginFileInjector):
             openstack_data['ansible'] = ansible_variables
         return openstack_data
 
-    def build_script_private_data(self, inventory_update, private_data_dir):
+    def build_script_private_data(self, inventory_update, private_data_dir, mk_cache=True):
         credential = inventory_update.get_cloud_credential()
         private_data = {'credentials': {}}
 
-        openstack_data = self._get_clouds_dict(inventory_update, credential, private_data_dir)
+        openstack_data = self._get_clouds_dict(inventory_update, credential, private_data_dir, mk_cache=mk_cache)
         private_data['credentials'][credential] = yaml.safe_dump(
             openstack_data, default_flow_style=False, allow_unicode=True
         )
         return private_data
 
+    def build_plugin_private_data(self, inventory_update, private_data_dir):
+        # Credentials can be passed in the same way as the script did
+        # but do not create the tmp cache file
+        return self.build_script_private_data(inventory_update, private_data_dir, mk_cache=False)
+
+    def get_plugin_env(self, inventory_update, private_data_dir, private_data_files):
+        return self.get_script_env(inventory_update, private_data_dir, private_data_files)
+
     def inventory_as_dict(self, inventory_update, private_data_dir):
-        credential = inventory_update.get_cloud_credential()
-
-        openstack_data = self._get_clouds_dict(inventory_update, credential, private_data_dir, mk_cache=False)
-        handle, path = tempfile.mkstemp(dir=private_data_dir)
-        f = os.fdopen(handle, 'w')
-        yaml.dump(openstack_data, f, default_flow_style=False)
-        f.close()
-        os.chmod(path, stat.S_IRUSR | stat.S_IWUSR)
-
         def use_host_name_for_name(a_bool_maybe):
             if not isinstance(a_bool_maybe, bool):
                 # Could be specified by user via "host" or "uuid"
@@ -2542,7 +2541,6 @@ class openstack(PluginFileInjector):
             fail_on_errors=True,
             expand_hostvars=True,
             inventory_hostname=use_host_name_for_name(False),
-            clouds_yaml_path=[path]  # why a list? it just is
         )
         # Note: mucking with defaults will break import integrity
         # For the plugin, we need to use the same defaults as the old script

awx/main/tests/data/inventory/plugins/openstack/env.json

@@ -1,3 +1,4 @@
 {
-    "ANSIBLE_TRANSFORM_INVALID_GROUP_CHARS": "never"
+    "ANSIBLE_TRANSFORM_INVALID_GROUP_CHARS": "never",
+    "OS_CLIENT_CONFIG_FILE": "{{ file_reference }}"
 }

awx/main/tests/data/inventory/plugins/openstack/files/openstack.yml

@@ -1,5 +1,3 @@
-clouds_yaml_path:
-- {{ file_reference }}
 expand_hostvars: true
 fail_on_errors: true
 inventory_hostname: uuid